Barb clamp with smooth bore

ABSTRACT

A barb clamp for connection to a flexible tube is taught, the flexible tube having an inner bore defined by a predetermined inner diameter for providing a fluid flow path. The barb clamp includes a barb connector having the same predetermined inner diameter as the flexible tube and a tapered end insertable into the tube. A sleeve and collet lock over the tubing and barb connector to prevent liquid material entering between the barb and tube. The tapered end of the barb connector terminates at a point so that there is no transition between the inner diameter of the tube and the inner diameter of the barb connector to provide no pressure differential in the tube between the outside and inside of the barb clamp.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-in-Part application of U.S. patentapplication Ser. No. 10/963,457 filed on Oct. 13, 2004 and nowabandoned, which claims priority of provisional patent application60/512,231 filed on Oct. 17, 2003 and now expired.

FIELD OF THE INVENTION

The present invention relates to a fastening device for a tubular body.

BACKGROUND OF THE INVENTION

The transfer of fluid through flexible tubing is widely used in variousenvironments. Ultimately, the flexible tubing is connected to the sourceof the gaseous or liquid fluid, the delivery site of the fluid, or toflexible tubing. At the ends of the flexible tubing, it is necessary toprovide a secure and leak proof connections. Although these requirementsare necessary in all environments using flexible tubing, it is criticalin the medical and pharmaceutical, food and beverage fields. In themedical and pharmaceutical fields flexible tubing and associatedconnections are used for luer fittings, quick connects, or sanitaryfittings such as used in blood pumps, oxygen concentrators, sleep apneaequipment, medical transport containers, IV bags, etc. In someenvironments, and especially in the medical field, it is imperative toabsolutely prohibit any liquids from getting between the tube and theconnection fitting at the connection point. Any gap or abrupt change atthe point of connection will entrap fluid, e.g. bio, blood, drugs,foodstuff, etc. This entrapment can cause growth of harmful bacteria.

SUMMARY OF THE INVENTION

The present invention addresses the aforementioned concerns. The presentinvention is an improved barb clamp used for joining a flexible tube toa barb fitting or connector, or straight lumen without a barb. And, inparticular, for joining flexible tube to a specially constructed barbfitting that provides minuscule or no transition differential betweenthe inner diameter of the tubing and the inner diameter of the barbfitting.

In one aspect of the invention the barb fitting tapers to a terminationpoint so that there is no transition between the inner diameter of thetube and the inner diameter of the barb fitting for preventing apressure differential in the tube between a portion of the tube in theimproved barb clamp and a portion of the tube outside of the barb clamp.

Other applications of the present invention will become apparent tothose skilled in the art when the following description of the best modecontemplated for practicing the invention is read in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING

The description herein makes reference to the accompanying drawingswherein like reference numerals refer to like parts throughout theseveral views, and wherein:

FIG. 1 is a sectional view of a current barb clamp;

FIG. 2 is a partial sectional view of an alternative to the current barbclamp;

FIG. 3 is an elevational view of a collet for the current barb clamp;

FIG. 4 is a sectional view of a sleeve for the current barb clamp;

FIG. 5 is a sectional view of an improved barb clamp according to thepresent invention;

FIG. 6 is a sectional view of an alternative embodiment of the improvedbarb clamp;

FIG. 7 is a perspective view of another alternative embodiment of theimproved collet and sleeve;

FIG. 8 is a perspective view of the embodiment shown in FIG. 7 having aportion sectioned off to illustrate certain figures;

FIG. 9 is a sectional view of the collet and sleeve of the barb clampshown in FIG. 7 in an unlocked position;

FIG. 10 is a sectional view of the collet and sleeve shown in FIG. 7 inthe locked position; and

FIG. 11 is a sectional view of the barb clamp shown in FIG. 10 lockedonto a tube.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 and 2 show the current barb clamp connector 10 for coupling abarbed fitting 12 and a flexible tube 14 and discussed hereafter. Thebarb fitting 12 is generally made of a non-metal material which allowsit to be heat welded to a proprolyene or ethylene medical orpharmaceutical bag. The same and similar materials can be used forbiotech, pharmaceutical, medical, and foodstuff fitting connections andmanifold applications. The fitting can also be made from other plasticsand stainless steel when required. As seen in FIGS. 1 and 2, the barbedfitting 12 may encompass different configurations but will generallyinclude at least one expanded or barbed end 16 for a 360° radialcompression connection to the flexible tube 14. If the barb clamp 10 isto be used in a medical or pharmaceutical environment, the barb fitting12 is preferably made from an FDA. (Food and Drug Administration)approved polypropylene, silicone, TPE, TPR, etc. The barb fitting 12 mayalso include a flanged portion 17 which defines a stop for the barbclamp 10.

The barb clamp 10 includes a collet 18 and a sleeve 20. The collet 18and the sleeve 20 are as shown in FIGS. 1-6 and are similar to thecollet and sleeve discussed in U.S. patent application Ser. No.10/100,519 filed on Mar. 18, 2002, now U.S. Pat. No. 6,796,586 issued onSep. 28, 2004.

The collet 18 is an essentially annular member having a through aperture19 for receiving the end of a tube 14 therein. The sleeve 20 is also anannular member with a through aperture 21 for receiving the end of thetube 14 as well as having a diameter for also receiving the collet 18therein.

Looking at FIG. 3 the collet 18 has an exterior surface 22 providingresilient means for radially contracting around the tube 14. The collet18 has a first end 23 forming a discontinuous annular ring. Along theexterior surface 22 and adjacent to the first end 23 is an annulargroove 26. Moving toward the second end 24 and beyond the annular groove26, the collet forms eight resilient tangs 28. The tangs 28 radiallyflare out or expand slightly at the second end 24 of the collet 18. Thetangs 28 begin to flare approximately at the mid section 27 of each tang28. The tangs 28 are formed by narrow through slots 25 extending fromthe second end 24 and terminating at the annular groove 26. The slots 25are shown in FIGS. 3 and 5 with rounded termination ends 25 a, however,the termination ends 25 a may have pointed ends, (not shown).

A small ramping ledge 30 projects above each termination end 25 a of thenarrow through slots 25. The small ledges 30 provide added strength tothe collet and also provide a stop means for the sleeve 20, as will bediscussed hereinafter. Between each small ledge 30 there is a recessedplanar portion 30 a extending into the annular groove 26. The eighttangs 28 form a resilient seal which allow the tangs to contract arounda tubular member 14. Between every other tang 28 there is a through slot29 which extends from the first end 23 to the mid-section 27 of theassociated tang 28. The through slots 29 may also have roundedtermination ends 29 a as shown in FIGS. 3 and 5 or pointed terminationends (not shown). The through slots 29 provide resiliency to the firstend 23 of the collet 18 without sacrificing durability. The interiorsurface 31 of the collet 18 is essentially smooth except for a shelf 32equally positioned on each tang 28 at the mid-section 27 for reasons tobe discussed further.

Looking at FIG. 4, the sleeve 20 has a smooth exterior annular surface34. The sleeve 20 has a first or bottom end 36 forming an arcuate baseto facilitate assembly to the collet 18. The interior surface 40 forms aslight outward taper at the second or top end 38 of the sleeve 20. Theinterior surface 40 is essentially smooth throughout the length of thesleeve 20 except for an annular projection 42 that extends from theinner surface. The annular projection 42 is sized and positioned on thesleeve 20 for disposition within the annular groove 26 of the collet 18to form a lock when the barb clamp 10 is engaged. Therefore, the annularprojection 42 is positioned proximate to the second or top end 38 of thesleeve 20.

The sleeve 20 is first placed over the end of the tube 14 so that thesecond or top end 38 of the sleeve 20 is spaced furthest away from thetube end the collet 18 is then placed on the tube 14 so that the firstend 23 of the collet 18 is closest to the sleeve 20. The expanded end 16of the barbed fitting 12 is then placed into the tube 14. The expandedend 16 of the barbed fitting 12 is sized for being snugly receivedwithin the interior of the tube 14. The collet 18 is then slid over thetube 14 having the expanded end 16 of the barbed fitting 12 therein. Theshelves 32 located on the interior surface 31 of the collet 18 is aretainer which forms a radial 360° compression around the tube 14 andunder the expanded end 16 of the barb fitting 12 so that the barbfitting 12 cannot easily move out of the tube 14. The sleeve 20 is thenslid over the collet 18 such that the first or bottom end 36 of thesleeve 20 initially encounters the first end 23 of the collet 18. As thesleeve 20 moves over the collet 18, the tangs 28 on the collet 18 arepushed radially inwardly into the tube 14 and barbed fitting 12, so thatthe annular shelf 32 of the collet 18 is pressed inwardly into the tube14 and barbed fitting 12 to provide a tight seal therebetween andthereby lock the annular shelf 32 under the barb 16. The sleeve 20continues over the collet 18 until the annular projection 42 on theinterior surface 40 of the sleeve 20 sits within the annular groove 26of the collet 18. The small ledges 30 on the exterior surface 34 of thecollet 18 provides a stop and lock to prevent the annular projection 42from moving out of annular groove 26. The barb clamp 10 “clicks” whenthe collet 18 and sleeve 20 lock together. The barb clamp 10 can thenonly be removed with the aid of a tool so that disconnection andleakages are prevented.

The improved barb clamp shown in FIGS. 5 and 6 has many of the samefeatures as discussed with regard to FIGS. 1-4. However, the improvedbarb clamp 10 further includes an engineered designed barb fitting 112which is designed to maintain the same cross sectional area of the boreor fluid passageway 100 a in the barb clamp 110 as the cross-sectionalarea of the bore or fluid passageway 100 in the tube 14 outside of thebarb clamp 10. The fluid passageway 100 outside of the barb clamp 110 isdefined by the inner bore of the tube 14. The fluid passageway 100 a inthe improved barb clamp 110 is defined by the inner bore of the barbfitting 112, 212. As can be seen in FIGS. 1 and 2, the cross-sectionalarea of the fluid passageway 100 of the tube 14 is reduced within thebarb clamp 10 as shown at 100 a in FIG. 1. The free end 50 of the barbfining 12 in the prior art has a blunt end 52 with a thickness thatcauses a transition in the cross-sectional area of the fluid passageway100 as the tubing 14 enters the barb clamp 10 and changes to the fluidpassageway 100 a. One problem encountered when designing a barbconnection is that it is generally necessary to have a smallercross-sectional area of the bore in the barb fitting 12 in order toinsert the barb fitting 12 into the tube 14. However, the improved clamp10 provides a barb fitting 112, 212 that has essentially the same borediameter as the tube 14, but can also easily be inserted into the tube14.

In the improved barb clamp 110, as shown in FIGS. 5 and 6, the barbfitting 112, 212 has an engineered bore size that has the samecross-sectional area as the bore 100 of the tubing 14. When the improvedbarb fitting 112, 212 are installed into a tube 14, there is notransition between the inner diameter of the tubing 14 and the innerdiameter of the fitting 112. As a result, there is no pressuredifferential on the tubing or in the fluid from outside to inside of thebarb clamp 110. Maintaining a constant pressure or a constant velocityof fluid throughout the system may be imperative in certain medicalapplications. To accomplish this, the free end 150 of the barb fitting112, 212 are gradually tapered to a sharp point 152. The sharp point 152on the free end 150 of the barb fitting 112 also allows for easyinsertion of the barb fitting 112 into the tube 14. As a result of thisconfiguration, liquid material can never get between the barb fitting112, or 212, and the tube 14.

FIG. 6 shows an alternative configuration of the barb clamp 110 whichstill maintains the same inner diameter of the passageway of the tube 14whether the tube 14 is within the barb clamp or not. In FIG. 6, it isshown that the barb fitting 212 may include a bumper stop 230 which isattached to the flange 17 to act as a separate stop for the tube 14while the flange 17 defines another stop for the collet 18, 218 andsleeve 20. The collet 218 may also be modified to have a tapered end 240to correspond with a tapered end 40 of the sleeve. Further the annularshelf 232 of the collet 218 may be reconfigured to extend further intothe tube 14 for a sturdier grip.

The collet 18 and sleeve 20 should be made of an FDA approved materialif the barb clamp 10 is in a medical or pharmaceutical environment. Thematerial should be resilient. Preferably the collet 18 is made ofacetyl, silicon, or polypropylene. The sleeve 20 is preferably made ofpolycarbonate, silicon, or polypropylene. The components of the improvedbarb clamp are made of such material as polypropylene that can besterilized in an autoclave for medical applications. Antimicrobialadditives may also be added to the plastic material used in themanufacturing of at least one of the barb connector, collet, and sleeve.

FIGS. 7-11 show an alternative configuration of the barb clamp 310according to the present invention. The barb clamp 310 of thisembodiment is made of the same materials as disclosed in the previousembodiments. Looking first a FIG. 11, a barb clamp 310 is assembled ontoa tube 314 for maintaining the tube 314 in fixed connection. The barbconnector or fitting 312 has a tubular configuration. The barb connector312 has a smooth inner bore 313 with a constant diameter therethroughdefining a fluid passageway therein. The constant diameter of the innerbore 313 of the barb connector 312 equals the predetermined innerdiameter 315 of the flexible tube 314. The barb connector 312 has afirst end for disposing into one end of the flexible tube 314. The firstend 322 has an outer angular or ramping surface 323 that commences fromthe inner surface 313 and extends radially outward away from the innersurface 313 defining a sharp point at the terminating end of the firstend 322. As a result, the first end 322 of the barb connector 312 has noedge perpendicular to the fluid passageway of the barb connector 312,and there is no pressure differential in the fluid passageway in thetube 314 inside or outside of the barb clamp 310 when installed. Theangular surface 323 extends along the entire radial periphery of thefirst end 322. The angular surface 323 terminates at a barbed point 324formed along the exterior surface. The barb fitting 312 may also includea flanged portion 326 spaced from the first end 322 which acts as a stopfor insertion of the barb connector 312 into the tube 314. Theconfiguration of the pointed first end 322 of the barb fitting 312provides a constant fluid passage diameter of the tube 314 whether thefluid passageway in the tube 314 is inside or outside of the barbconnector 312.

The barb clamp 310 includes a collet 318 and a sleeve 320. The collet310 and the sleeve 320 are as shown in FIGS. 7-11. In the illustratedembodiment, the collet 318 and sleeve 320 are connected together byfrangible tabs 328 as will be discussed hereinafter. The collet 318 isan annular member having a through aperture 319 for receiving the end ofthe tube 314 therein. The outer surface 330 of the collet 318 has abi-level configuration wherein the diameter of the outer surface 330 aadjacent the first end 332 is less than the diameter of the outersurface 330 b adjacent the second end 334. The first and second outersurfaces 330 a, 330 b are separated and defined by a ledge 336positioned at the midpoint of the collet 318.

The interior surface 319 of the collet 318 has an essentially smoothradial surface except at the first end 332, wherein an annular ridge 338is positioned. The annular ridge 338 is defined by a lead-in annularsurface 340 that angles inwardly to the reduced diameter of the ridge338. The angle leading edge 340 facilitates the entry and assembly ofthe barbed end 322 of the connector 312 and tube 314. The second end 334of the collet 318 has a radial surface perpendicular to the fluidpassageway. A plurality of the frangible tabs 328 are connected to andextend from the radial surface 334 of the second end. Opposing ends ofthe frangible tabs 328 are also connected to an inner surface of thesleeve 320 as will be discussed hereinafter.

Elongate through slits 342 commence at and are opened to the first end332 of the collet 318. The plurality of slits 342 are equally spacedalong the circumference of the collet 318. The slits 342 have elongatedlateral edges 343 a 343 b that are spaced from each other forming a gaptherebetween. The slits 342 extend approximately o-thirds of the axiallength way into the body of the collet 318 from the first end 332. Byexample only, the slits 342 are positioned directly in alignment withthe frangible tabs 328.

The second end 334 of the collet 318 also includes a plurality ofthrough slits 344. The slits 344 are configured the same as the slits342. The slits 344 also include lateral spaced edges 345 a, 345 b. Theslits 344 extend and are opened to the second end 334 of the collet 318and extend two-thirds of the axial length into the body of the collet318. The slits 344 are equally spaced between adjacent slits 342.Therefore, there is a center portion of the collet 318 into which bothsets of slits 342, 344 extend. The slits 342,344 allow for a resilientseal around the tube 314 when the barb clamp 310 is in a lockedposition.

The sleeve 320 has a smooth exterior surface 350. The interior surface351 of the sleeve has a radial lip 352 formed at the first end 354 ofthe sleeve. The interior surface 351 has an expanded radial section 358adjacent to the lip 352. The expanded section 358 has an expanded radialdiameter for accommodating the second section 330 b of the exterior ofthe collet 318 when the barb clamp is in the locked position. Theexpanded section 358 terminates at a ledge 360 defined by a reduceddiameter portion 362. Axially, the reduced diameter portion 362 isfollowed by a ramped portion 364 that ramps outwardly to an expanded endportion 366. The expanded end portion 366 is adjacent to the second end356 of the sleeve 320. Opposing end portions of the frangible tabs 328are positioned and connected to the wall of the interior expanded endportion 366 of the sleeve. The connection of the frangible tabs 328 tothe collet 318 and sleeve 320 form a gap 329 between the second end 356of the sleeve 320 and the second end 334 of the collet 318 so that thefrangible tabs 328 are the only connection between the collet and sleevewhen the barb clamp is in the unlocked position. The position of thefrangible tabs 328 relative to the collet 318 and sleeve 320 allow forbreakage of the frangible tabs 328 from the collet 318 with apredetermined applied force.

For installation, the attached collet 318 and sleeve 320 are slippedonto the end of the tube 314 with the sleeve 320 end placed on the tube314 first. The barb fitting or connector 312 is inserted into the end ofthe tube 314 leading with the pointed barbed end 322. Once the barbconnector 312 is tightly installed into the end of the tube 314, thecollet 318 is slid back over that end of the tube 314 enclosing both theend of the tube 314 and the barb connector 312. A locking instrument canbe used to break the frangible tabs 328 to detach the sleeve 320 fromthe collet 318 and slide the sleeve 320 over collet 318. Although thetabs 328 are broken away from the collet 318, the portions of the tabs328 on the inside surface 366 of the sleeve remain in tact and connectedto the sleeve 320.

As the sleeve 320 moves over the collet 318, the second end 334 of thecollet 318 breaks off the frangible tab portions 328 attached to theinner surface 362 of the sleeve 320. As the sleeve 320 continues itsaxial movement over the collet 318, the second end 334 of the colletfollows the ramp 364; and the slits 344 squeeze together eliminating thegap between the side edges 345 a, 345 b to provide a resilient sealaround the tube 314. The sleeve 320 continues to move over the collet318 until the second end 334 of the collet 318 is locked and abuts belowthe radial lip 352 in the sleeve. The radial lip 352 stops further axialmovement of the sleeve 320 relative to the collet 318. In the lockedposition as shown in FIGS. 10 and 11, the second outer surface 330 b ofthe collet 318 is adjacent to the expanded section 358 in the sleeve320.

The ledge 336 on the collet 318 snaps over and is held on the innerledge 360 of the sleeve 320. The reduced diameter portion 362 of thesleeve 320 contracts the first section 330 a of the collet 318 andremoves the gap between the side edges 343 a and 343 b of the slit 342.The reduced section 362 is positioned to affect the contraction of eachof the gaps 342 and 344. The tab portions 328 that remain connected tothe sleeve 320 grip the outer surface 330 a of the collet 318 adjacentto the first end 332. When the sleeve 320 is locked over collet 318, thebarb fitting 312 and the tube 314, there is a 360° radial compressionconnection of the tube 314.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiments but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims, which scope is to be accorded the broadestinterpretation so as to encompass all such modifications and equivalentstructures as is permitted under the law.

1. A barb clamp for a flexible tube having a predetermined innerdiameter defining a passageway therein and an outer surface, the clampcomprising: a barb connector having a tubular configuration with a firstend for disposing within an end of the tube, the barb connector having asmooth inner bore with a constant diameter defining a fluid passagewaytherein, said constant diameter of the inner bore equal to thepredetermined inner diameter of the flexible tube; a cylindrical collethaving a through aperture slidable over the first end of the barbconnector, said collet having a first end, a second end, and inner andouter surfaces, said inner surface of the collet having acircumferential ridge at a first end of the through aperture, said outersurface of the collet having a bi-level configuration wherein thediameter of the outer surface adjacent the first end is less than thediameter of the outer surface adjacent the second end defining a ledgetherebetween; and a cylindrical sleeve having a through center aperturefor slidably receiving said collet, said sleeve having a first and asecond end, said second end of the sleeve connected to the second end ofthe collet by frangible tabs, said through center aperture of the sleevedefined by an inner surface, said inner surface having a firstcircumferential portion, a second circumferential portion, a thirdcircumferential portion and a fourth circumferential portion, said firstcircumferential portion having an expanded diameter and located adjacentto the second end of the sleeve, the frangible tabs having one end ofeach tab connected to the first circumferential portion, said secondcircumferential portion located adjacent to the first circumferentialportion and ramping to a reduced diameter portion defined by the thirdcircumferential portion, said third circumferential portion terminatingat a ledge at a midpoint of the sleeve.
 2. The barb clamp of claim 1,wherein the outer surface of the first end of the barb connector isradially angled to define a ramp to a barbed end, the ramp terminatingat the barbed end and forming a sharp point at the first end of the barbconnector.
 3. The barb clamp of claim 2, wherein the first and secondends of the collet have through slits formed therein, the through slitsdefined by lateral edges having a gap therebetween, and wherein thethrough slits at the second end are offset with the slits at the firstend.
 4. The barb clamp of claim 3 wherein the slits extend from and areopen to their respective ends and extend approximately two thirds intothe axial length of the collet.
 5. The barb clamp of the claim 4,wherein the frangible tabs are positioned in axial alignment with thethrough slits at the first end of the collet.
 6. The barb clamp of claim5, wherein the ledge formed in the inner surface of sleeve receives theledge on the outer surface of the collet when the barb clamp is in alocked position.
 7. The barb clamp of claim 1, wherein the fourthcircumferential portion commences at the ledge and extends to a radiallip at the first end of the sleeve.
 8. The barb clamp of claim 7,wherein the radial lip defines a stop for axial movement of the colletrelative to the sleeve.
 9. The barb clamp of claim 1, wherein thefrangible tabs on the sleeve grip the outer surface of the collet whenthe barb clamp is in a locked position.
 10. The barb clamp of claim 1,wherein the collet has a flat surface positioned perpendicularly at thesecond end and one end of the frangible tabs is connected to the flatsurface and the other end of the frangible tabs is connected to thefirst circumferential portion.
 11. The barb clamp of claim 10, whereinthe ends of the frangible tabs connected to the first circumferentialportion grip the exterior of the collet when the barb clamp is in alocked position.